What happened
On 5 December 2003, a Piper PA-32-260, registration ZS-ELX, was operating a private flight from Cape Town Aerodrome to Mossel Bay Aerodrome. During the journey, the aircraft landed at Upington Aerodrome for refueling. After the tanks were filled to capacity, the pilot attempted to restart the engine to continue the flight.
During this startup sequence, a fire ignited within the engine nacelle. The pilot immediately responded by switching the master switch to the off position and evacuating the aircraft. Personnel at the aerodrome arrived quickly to assist, using portable fire extinguishers to suppress the flames. No injuries were reported, and no fatalities occurred during the incident.
The investigation
The investigation focused on the circumstances surrounding the ignition of the fire. While no formal on-site investigation was conducted, inspections by the Approved Maintenance Organisation (AMO) that recovered the aircraft revealed that the cowlings had sustained minor burn damage. Additionally, various electrical wiring and the ignition harness within the engine nacelle area showed clear signs of fire damage.
Findings
Investigators determined that the fire was caused by the pilot over-priming the engine. This action led to an accumulation of excess fuel within the manifold and the lower cowling area, which subsequently ignited during the engine start process. The high ambient temperature of 43°C was also identified as a contributing factor to the incident.